The invention relates to a microwave device in which the electromagnetic waves propagates in a non-reciprocal manner, due to a magnetised gyromagnetic medium located in the propagation path.
In non-reciprocal devices, the direction along which propagation is achieved with low loss (insertion loss) will be called the "direct direction" according to current practice, while the opposite direction along which high attenuation is obtained (isolation) will be called the "reverse direction."